Steps to reproduce

1. Open preferences
2. Navigate to timezone preferences
3. Look for an option to always load timezone from browser/OS
4. Find the only similar "Load from current browser setting"
5. Try it
6. Notice this only affects at the moment and not next time when you login from a different browser in a different timezone

Expected behavior
I would expect "Always load from current browser setting" option to be there and always keep timezone in sync with the current browser setting. This is useful when you travel a lot between timezones.

Current behavior
There is no such option. Either you can use your wiki timezone, or you can use your homeland, or you can switch timezone in preferences every time you switch timezone in reality.